✏️ Latest scribble · October 28, 2026
How to Randomize a Classroom Seating Chart
Fair methods plus when never to randomize.
❓ Is random seating fair? ❓ How often should I randomize? ❓ What if students hate the draw?
Read this postThe PrimeFreeTools blog
Guides, walkthroughs and tool news. Every post is filed under the tool or topic it belongs to.
Sep 17, 2026
HMAC Generator: A Secret-Signed Message via Web Crypto
HMAC with secret and hash.
Read postSep 17, 2026
The Modern Timezone Meeting Planner: How Distributed Remote Teams Coordinate Without Burnout
Coordinating synchronous meetings across three or more timezones is one of the quickest ways to erode remote team culture. What starts as…
Read postSep 17, 2026
ISBN Validator: ISBN-10 vs ISBN-13 Checksums, Decoded
Confirms ISBN-10 and ISBN-13 checksums.
Read postSep 17, 2026
IBAN Validator: Is That Bank Number Even Real
Check IBAN syntax and checksums per country.
Read postSep 17, 2026
Luhn Mock Cards: Test Checkout With Numbers That Pass the Check
Valid test cards for sandbox checkouts.
Read postSep 17, 2026
UUID Checker: Version, Variant, and Well-Formedness in One Look
Confirm an identifier fits standard UUID syntax.
Read postSep 16, 2026
JWT Decoder: See What an Auth Token Is Really Claiming
Split tokens into header, payload, and signature.
Read postSep 16, 2026
Bcrypt Hash: Test Password Hashing Without a Server
Hash strings for password handling tests.
Read postSep 16, 2026
Port Scanner Reference: What 22, 443, and 3389 Actually Are
Interactive directory of common TCP/UDP ports.
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